Ver broke QHY10 TEC Control

After installing and running my QHY10 camera, it seems that the TEC control is no longer functioning properly. Setting a -20C temperature (as is my usual) it took over 1 hour for the TEC control on the camera to respond and get to the selected temperature. I have never had to wait this long - usually 5-10 minutes tops. I re-installed and everything is fine.

I can’t seem to duplicate this. If you can attach some logs that will be helpful.


I have attached two log files, one using and the other

Using the following sequence was executed:

Connect cables to camera
Connect camera @ SGP
Set cooler ‘On’
Set Cool down to -10c in 10min

@5min, TEC at 16%
@8min, TEC at 33%
@10min, TEC at 33%, temp at -8.3c
Camera reached -10 about 1 minute later. Total time to -10c -> 11 minutes

Set Warm up to 20c in 5min
Camera reached 17.6c in that period.

Using the following sequence was executed:

Connect cables to camera
Connect camera @ SGP
Set cooler ‘On’
Set Cool down to -10c in 10min

@5min, TEC at 7%; temp at 12.1
@8min, TEC at 13%; temp at 6.5
@10min, TEC at 15%, temp at 4.6
Selected period end
@15min, TEC at 25%; temp at -3.7
@20min, TEC at 28%’; temp at -7.7
@25min, TEC at 30%; temp at -9.3
Camera did not reach specified temperature in 30 minutes.

Set Warm up to 20c in 5 min
@2.5 min, TEC at 25%; temp at -8.9
@5.0 min, TEC at 0%, temp at -6.8
Just like the long cool down, there was a long warm up!!

I tried to capture the temperature of an image at the end of the run (so the log is longer) but I had the wrong file attributes set (didn’t capture temp).

sg_logfile_20170521143813.txt (23.0 KB)
sg_logfile_20170521151354.txt (74.0 KB)

I’ll pull out my QHY11 in the next day or two and test with a physical device. However being ASCOM this would likely be broken for all ASCOM devices. I can’t really think of anything that different between .21 and .23 that would cause this that wouldn’t manifest with a simulator but I’ll give it a shot and see what happens.


The TEC control on the QHY10 is almost non-existent. As soon as the camera is connected, it starts cooling to some default value. You can set the temperature to something else but you can’t turn the cooler on or off except by connecting or disconnecting. So if SGP where broken (unlikely), it would be in setting the temperature.

Yes, I agree with you about the QHY10 immediately starting the TEC, but you can use SGP to control it. Once the camera is connected I use SGP to turn the TEC on. Now it is probably on already, but SGP doesn’t know that (maybe). Anyhow, I can then set a temperature or use the Cool Down/Warm Up controls to establish a particular temperature. I have been doing this for at least a couple of years with no problems until

I have the QHY10 driver sources and the ASCOM cooler on/off call does nothing in this driver. So SGP can set the temperature but that is it.

So that’s interesting :confused: how then I am seeing the Cool Down working? I can set a Cool Down temperature using SGP and over the time specified I reach that temperature? I’ll need to experiment more with this, but I can tell you that the behavior of and is different.

FWIW cooling on my ASI1600mm-c also seems to sometimes take a long time (10m+) with where it used to usually finish in the programmed 4minutes. Did any code change related to cooling in .23?

The only thing that changed was how often we ask the camera for the temperature. It appears that this polling is what the QHY cameras used to do temperature control. IE if we never polled the camera would never cool. I don’t believe the ASI is structured in such a manner. For the QHY this happened regardless of the “Cool Down Time”.

I would also assume that warmer temps are making it more difficult to cool your camera. My ASI1600 has never cooled quickly or very deeply.



I was about to post my own issue re slow cooling of my QHY10 using SGP, but saw this thread. I believe this is a real issue, so I add details here…

When using my QHY10 with SGP, the camera takes an extraordinary amount of time to cool down (~ 60mins to -20c). It also seems to take a long time to warm up using SGP.

I do not think this is a camera or ambient temp issue. It is winter and cold where I am. I have used SGP happily and extensively for quite some time, and it works extremely well with my QSI camera.

The QHY10 also cooled down quickly (actually too quickly) when I tested with Nebulosity 3 ( which I no longer use) using the same ASCOM driver, albeit the camera does take a while to stabilise on the correct temperature. Also, the slow warming does not seem to be indicative of a camera fault or ambient temp issue.

In addition, SGP reports that the camera is nowhere near capacity ( 1-15 %), even when it is miles from the required temp.

I have logs, but they don’t seem to say much.

Any advice?